Persistent Scatterer Interferometry (PSI), a remote sensing technique, is used for detecting surface deformation in the cities of Prague and Ostrava. PSI is able to detect vertical movements with an accuracy of less than 1 mm for a long time series of the SAR data, but the maximum detectable rate of movement is only a few centimetres per year. This technique is quite suitable for detecting recent movements in most Prague localities. On the other hand, in Ostrava and its surroundings, affected by undermining, where subsidences (1992-2006) amount to decimetres per year, movements cannot be fully detected by the PSInSAR technique. The paper presents results of analysing PSI data for two localities in Prague and one locality in the Ostrava areas. The localities are strictly situated in built-up areas with many suitable reflectors. Data from the ERS-1/2 and ENVISAT satellites covering a 13-year period for the Prague (1992-2005) and a 14-year period for the Ostrava (1992-2006) area were used. Annual movement velocities and time-series of reflectors were determined. At these three localities, where different types of movements were identified, the application and possible limitations of PSI in urban areas are shown., Pavel Kadlečík, Vladimír Schenk, Zuzana Seidlová and Zdeňka Schenková., and Obsahuje bibliografii
a1_Cities contain only a low representation of natural and semi-natural habitats, existing in fragments surrounded by built-up areas. In 2003-2004, we surveyed butterflies and Zygaenidae moths in 21 reserves and 4 parks within the city of Prague, Czech Republic, situated from the periphery to city centre. A total of 85 species (47% of the Czech fauna of the study groups) was detected, 22 of them being of conservation concern. Ordination analyses of the local assemblages revealed that the richest sites were large, situated far from the city centre, on alkaline bedrocks, south- to southwest oriented, and hosting high numbers of vegetation types and vascular plant species. We then used generalised linear models to fit responses of individual species to the main ordination gradient, corresponding to increasing urbanisation. Out of 60 species that met criteria for the modelling, none responded positively to urbanisation. Twenty displayed negative linear response; these urban avoiders contained a surplus of mesophilous species presumably preferring rural landscapes. Further 29 species (suburban adaptable) responded in domed manners, peaking at the city periphery. Prevailing among them were xerophilous specialists inhabiting large grassland reserves at the Prague outskirts. Finally, eleven urban tolerant species did not respond to urbanisation at all, containing three highly mobile species, three xerothermophilous specialists, and five species utilising shrubs or trees and finding suitable conditions even in urban parks. Suburban adaptable butterflies apparently benefit from such suburban environments as gardens, road or railway verges, collectively increasing the connectivity of remnants of seminatural habitats. The fact that arboreal species persist even in urban parks, whereas common grassland species are absent there, implies that the quality of urban habitats might be increased by a more sensitive management of, a2_urban green spaces, such as leaving aside small temporary fallows or adapting lawns mowing schemes., and Martin Konvicka, Tomas Kadlec.